1. Field of the Invention
The present invention relates to a filter structure. More specifically, the present invention discloses a filter structure that can be applied to a flashlight and filters that can be changed as needed.
2. Description of the Prior Art
The light of a common flashlight is white. Although white light is used for night illumination, it is not suitable for some other special illumination. For example, white light, when used at night, can easily be spotted. Therefore, a filter that can alter the color of illumination is needed.
If a filter is placed on the top of the light source, and if the filter is red, the light coming out of the flashlight is red. Red light would be suitable for night illumination, so that the user cannot be easily spotted. However, the visibility provided by red light is poor. Visibility could be improved, if blue light is applied. Thus, filters can provide many functions to a flashlight.
However, it would be inconvenient if the user had to change the filter when a different situation occurred. Therefore, how to solve the problems mentioned above is of concern.
Due to the inconvenience and trouble of existing products, a new generation of flashlight is needed which is provided with a changeable filter structure.